Nearly half of businesses are preparing to update desktops to Windows Vista, with small businesses moving the fastest, according to a new report. Moreover, about 35 percent of companies are currently implementing or have implemented Vista already, compared to 12 percent last February, the report said.

The number of organisations evaluating and testing Vista increased from 29 percent in February 2007 to 48 percent by early November 2007, according to the survey, commissioned by reseller CDW and based on information collected by Walker Information.

The report is the third of a wave of reports on Vista adoption that CDW has carried out. In the latest phase of release, which tracked Vista adoption from 31 October 31 until 7 November, 2007, small businesses comprised 53 percent of those companies either using or evaluating Vista. The higher-education segment came in second, with 49 percent reporting that they are evaluating or using the OS, while medium-to-large businesses were third, with 48 percent.

Because of lingering hardware and application compatibility issues between existing company IT assets and Vista, CDW still advises customers to move to Vista on a case-by-case basis, said David Cottingham, director of product and partner management at CDW. In the case of small businesses, they may not have the application or hardware dependencies on Windows XP that larger businesses have.

"There are still definitely concerns when you get into custom applications in industries that will run on XP," he said. "If [companies] have custom applications that don't run on Vista yet, they're going to stay on XP."

CDW is still selling both XP and Vista, but Cottingham said the company does not have data on which version of the OS is selling more now that Vista has been available to businesses for more than a year. In September, Microsoft had to extend the OEM license for XP for five more months through June 30, 2008, because of customer demand for the OS. Microsoft had planned to stop selling XP through OEMs and retailers on January 31.

For its part, Microsoft has made strides to resolve compatibility issues with updates to Vista, and the numbers from CDW's survey seem to reflect that. In February, 50 percent of companies said they were buying additional hardware and software assets to migrate to Vista; by November, that number was down to 44 percent.

Many believe it's inevitable that any businesses currently running XP will eventually move to Vista; it's just a matter of when. The release of Vista Service Pack 1 (SP1), which is scheduled to be generally available by the end of March, should serve to increase the numbers of companies adopting Vista. Microsoft on Friday issued a public refresh of the first release candidate for SP1, which suggests the software update will be in its final release according to schedule.

However, there is some belief among industry watchers that if Microsoft releases the next version of Windows, code-named Windows Vista 7, by its target of late next year to early 2010, some businesses may opt to skip Vista and move directly from XP to Windows 7 instead.